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GHSA-xhfx-hgmf-v6vp

October CMS vulnerable to Potential Host Header Poisoning on misconfigured servers

Also known asCVE-2021-21265
Published
Mar 10, 2021
Updated
Jul 8, 2026
Affected
1 pkg
Patched
1 / 1
Exploits
None indexed

Blast Radius

1 pkg affected
🐘october/backend

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Packagist packages — download data is not available via public APIs for these ecosystems.

Description

Impact

When running on servers that are configured to accept a wildcard as a hostname (i.e. the server routes any request, regardless of the HOST header to an October CMS instance) the potential exists for Host Header Poisoning attacks to succeed. See the following resources for more information on Host Header Poisoning:

Patches

A feature has been added in v1.1.2 to allow a set of trusted hosts to be specified in the application.

Workarounds

Alternative Workaround

Check to make sure that your web server does not accept any hostname when serving your web application.

  1. Add an entry called testing.tld to your computer's host file and direct it to your server's IP address
  2. Open the address testing.tld in your web browser
  3. Make sure an October CMS website is not available at this address

If an October CMS website is returned, configure your webserver to only allow known hostnames. If you require assistance with this, please contact your server administrator.

References

Reported by Abdullah Hussam

For More Information

If you have any questions or comments about this advisory:

Threat Assessment

<img width="1108" alt="Screen Shot 2021-01-15 at 4 12 57 PM" src="https://user-images.githubusercontent.com/7253840/104783859-92fb3600-574c-11eb-9e21-c0dc05d230a9.png">

Affected Packages

1 total 1 fixed
EcosystemPackageVulnerable rangeFix
🐘Packagistoctober/backendall versions1.1.2

Detection & mitigation playbook

Open-source dependency
  1. Detect

    Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for october/backend. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.

  2. Fix

    Update october/backend to 1.1.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-xhfx-hgmf-v6vp is resolved across your whole dependency graph.

  3. Workarounds

    If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

  4. How O3 protects you

    O3 pinpoints whether GHSA-xhfx-hgmf-v6vp is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Tailored to GHSA-xhfx-hgmf-v6vp. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

### Impact When running on servers that are configured to accept a wildcard as a hostname (i.e. the server routes any request, regardless of the HOST header to an October CMS instance) the potential exists for Host Header Poisoning attacks to succeed. See the following resources for more information on Host Header Poisoning: - https://portswigger.net/web-security/host-header - https://dzone.com/articles/what-is-a-host-header-attack ### Patches A feature has been added in v1.1.2 to allow a set of trusted hosts to be specified in the application. ### Workarounds - Apply https://github.com/oc
O3 Security · Impact-Aware SCA

Is GHSA-xhfx-hgmf-v6vp in your dependencies?

O3 detects GHSA-xhfx-hgmf-v6vp across Packagist dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.